Cytogenetic effect of caffeine in the micronucleus test

Relevance. The consumption of caffeine-containing food in the modern world must necessarily be safe for humans, including should not affect the hereditary material of the body. Objective: to determine the possible effect of caffeine at the cytogenetic level by the micronucleus method on erythrocytes. Materials and Methods. The objects for the study were non-linear mice, which were divided into 6 groups - one control group and 5 experimental groups. The first experimental group and the second in the experiment received caffeine in doses of 40 mg/kg and 100 mg/kg.The control group received saline. Caffeine was administered orally. The mutagen (dioxidine) was injected intraperitoneally. On the 5th day of the experimental study, we performed blood sampling for cytogenetic analysis. Results and Discussion. Our study of the caffeine preparation made it possible to determine the following patterns. Firstly, when administered within 5 days, caffeine at a dose of 40 and 100 mg/kg did not cause an increase in the number of micronuclei in erythrocytes in mice. Secondly, the combined use of caffeine (both at a dose of 40mg/kgand at a dose of 100 mg / kg) and dioxidine significantly increased the level of micronuclei in comparison with the control group. Thirdly, caffeine at a dose of 40mg/kgdid not increase the mutagenic activity of dioxidine, but a dose of caffeine of 100mg/kgwhen combined with a mutagen led to a significant increase in the level of cytogenetic damage. Conclusion. According to our data, caffeine in the experimental study was not a mutagen, but at a dose of 100 mg/kg it represented a comutagenic effect.

Chemistry, lung toxicity and mutagenicity of burn pit smoke-related particulate matter

Background Open burning of anthropogenic sources can release hazardous emissions and has been associated with increased prevalence of cardiopulmonary health outcomes. Exposure to smoke emitted from burn pits in military bases has been linked with respiratory illness among military and civilian personnel returning from war zones. Although the composition of the materials being burned is well studied, the resulting chemistry and potential toxicity of the emissions are not. Methods Smoke emission condensates from either flaming or smoldering combustion of five different types of burn pit-related waste: cardboard; plywood; plastic; mixture; and mixture/diesel, were obtained from a laboratory-scale furnace coupled to a multistage cryotrap system. The primary emissions and smoke condensates were analyzed for a standardized suite of chemical species, and the condensates were studied for pulmonary toxicity in female CD-1 mice and mutagenic activity in Salmonella (Ames) mutagenicity assay using the frameshift strain TA98 and the base-substitution strain TA100 with and without metabolic activation (S9 from rat liver). Results Most of the particles in the smoke emitted from flaming and smoldering combustion were less than 2.5 µm in diameter. Burning of plastic containing wastes (plastic, mixture, or mixture/diesel) emitted larger amounts of particulate matter (PM) compared to other types of waste. On an equal mass basis, the smoke PM from flaming combustion of plastic containing wastes caused more inflammation and lung injury and was more mutagenic than other samples, and the biological responses were associated with elevated polycyclic aromatic hydrocarbon levels. Conclusions This study suggests that adverse health effects of burn pit smoke exposure vary depending on waste type and combustion temperature; however, burning plastic at high temperature was the most significant contributor to the toxicity outcomes. These findings will provide a better understanding of the complex chemical and combustion temperature factors that determine toxicity of burn pit smoke and its potential health risks at military bases.

Concise Synthesis of Alternariol and Alternariol-9-monomethyl ether as well as their D3-Isotopologues

Alternariol (AOH) and alternariol-9-monomethyl ether (AME) are two secondary metabolites of Alternaria fungi which can be found in various foodstuff like tomatoes, nuts, and grains. Due to their toxicity and potential mutagenic activity the need for the development of high-throughput methods for the supervision of AOH- and AME-levels is of increasing interest. As the availability of both native and labeled AOH and AME analytical standards is very limited we herein wish to present a novel concise approach towards their synthesis employing a ruthenium-catalyzed ortho-arylation as the key step. Finally, we demonstrate their suitability as internal standards in stable-isotope dilution assay (SIDA)-HPLC-MS/MS analysis commonly used for the quantification of the natural products in food and feed.

Antimutagenic, anti-inflammatory, and antioxidative activities of the juice of Vitis ficifolia var. Ganebu, a woody vine in the grape family, known as Ryukyu-ganebu in Japan

Background Mutation, inflammation, and oxidative damage including lipid-peroxidation are factors involved in the development of cancer. We investigated the antimutagenic, in vivo and in vitro anti-inflammatory, and antioxidative effects of the juice of Vitis ficifolia var. ganebu (known as Ryukyu-ganebu in Japan) harvested in Kuchinoshima island (hereafter, the juice is referred to as ganebu-K) in comparison with the juice of Vitis coignetiae (crimson glory vine, known as yamabudo in Japan; hereafter, the juice is referred to as yamabudo) which we found antimutagenic and anti-inflammatory effects. Results Ganebu-K inhibited the mutagenic activity of several carcinogens, MeIQx, IQ, Trp-P-2(NHOH), and MNNG, model compounds of tumor initiation. Using S. typhimurium YG7108, a strain lacking O6-methylguanine DNA methyltransferases, ganebu-K showed no significant inhibition of the mutagenicity of MNNG. Thus, DNA repair of O6-methylguanine produced by MNNG might be an antimutagenic target of the components in ganebu-K. Topical application of ganebu-K to the dorsal sides of mice resulted in potent suppression of acute edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Ganebu-K, but not yamabudo, exhibited significant inhibition of the induction of prostaglandin E2 (PGE2) induced by TPA. Components contained in ganebu-K, but not in yamabudo, might be responsible for the inhibition of the induction of PGE2. Ganebu-K inhibited in vivo lipid peroxidation and decreased the level of glutamic oxaloacetic transaminase induced by CCL4 treatment. Conclusions These results suggest that the active components in ganebu-K juice are not the same as those in yamabudo, and the components in ganebu-K are attractive candidates as chemopreventive agents.

Gut microbiota of bats: pro-mutagenic properties and possible frontiers in preventing emerging disease

Bats are potential natural reservoirs for emerging viruses, causing deadly human diseases, such as COVID-19, MERS, SARS, Nipah, Hendra, and Ebola infections. The fundamental mechanisms by which bats are considered “living bioreactors” for emerging viruses are not fully understood. Some studies suggest that tolerance to viruses is linked to suppressing antiviral immune and inflammatory responses due to DNA damage by energy generated to fly. Our study reveals that bats' gut bacteria could also be involved in the host and its microbiota's DNA damage. We performed screening of lactic acid bacteria and bacilli isolated from bats' feces for mutagenic and oxidative activity by lux-biosensors. The pro-mutagenic activity was determined when expression of recA increased with the appearance of double-strand breaks in the cell DNA, while an increase of katG expression in the presence of hydroxyl radicals indicated antioxidant activity. We identified that most of the isolated bacteria have pro-mutagenic and antioxidant properties at the same time. This study reveals new insights into bat gut microbiota's potential involvement in antiviral response and opens new frontiers in preventing emerging diseases originating from bats.

Evaluation Of The Mutagenic Potential Of The Polyphenol Extract From Blueberries In The Ames Test

In this research, mutagenic properties of blueberry polyphenol extract were studied in gene mutation induction test (Ames test) on four strains of Salmonella typhimurium TA98, TA100, TA1535, TA1537. None of the strains of Salmonella typhimurium showed statistically reliable dose-dependent increase in number of revertant colonies in the presence of investigated drug in the studied dose range from 4,0 to 40,0 mg/ml relative to baseline of spontaneous mutations. The blueberry extract does not have any mutagenic activity in the researched dose range in relation to TA98, TA100, TA1535, TA1537 strains of Salmonella typhimurium.

Study of Some Physiological and Genetic Changes Using the Soybean (Glicine max (L) MEER) Test System

Anthropogenic pressure on the biosphere has become a common process of the 21st century. Among substances synthesized by humans, genotoxic agents which include pesticides are considered to be particularly dangerous. The number of pesticides used in agriculture is gradually increasing, accumulating and circulating in the biosphere. The use of pesticides is accompanied by their involvement in food chains and accumulation in individuals. They are characterized by a fairly high stress index and cause genetic changes in living organisms. Various test methods have been developed to study these issues. B. Wig and Al. Podok suggested a genetic line for soybean containing a mutation of the chlorophyll-synthesizing gene. The genetic line is characterized by a phenotypic effect. Indicator, genetic line owner soybean, diploid, heterozygous, give three phenotypically different sprouts: green (genotype Y11 Y11), lettuce-color (genotype Y11 y11) and yellow (genotype y11 y11). 1: 2: 1 ratio is observed between the sprouts. This type of ratio is typical for incomplete dominance. Through the spots detected on the leaves it is possible to study the recombinogenic and mutagenic activity in soybean induced by chemical and physical factors and to record the induced changes in somatic cell. Using these systems, we first studied the effects of pesticides karate and Bordeaux on plant growth and sprouting processes and the genetic changes induced by their influence. Both pesticides had an inhibitory effect on physiological processes, also, the frequency of direct mutations was determined by the "dose-effect" phenomenon.

Expansion of targetable sites for the ribonucleoprotein-based CRISPR/Cas9 system in the silkworm Bombyx mori

Background With the emergence of CRISPR/Cas9 technology, multiple gene editing procedures became available for the silkworm. Although binary transgene-based methods have been widely used to generate mutants, delivery of the CRISPR/Cas9 system via DNA-free ribonucleoproteins offers several advantages. However, the T7 promoter that is widely used in the ribonucleoprotein-based method for production of sgRNAs in vitro requires a 5′ GG motif for efficient initiation. The resulting transcripts bear a 5′ GG motif, which significantly constrains the number of targetable sites in the silkworm genome. Results In this study, we used the T7 promoter to add two supernumerary G residues to the 5′ end of conventional (perfectly matched) 20-nucleotide sgRNA targeting sequences. We then asked if sgRNAs with this structure can generate mutations even if the genomic target does not contain corresponding GG residues. As expected, 5′ GG mismatches depress the mutagenic activity of sgRNAs, and a single 5′ G mismatch has a relatively minor effect. However, tests involving six sgRNAs targeting two genes show that the mismatches do not eliminate mutagenesis in vivo, and the efficiencies remain at useable levels. One sgRNA with a 5′ GG mismatch at its target performed mutagenesis more efficiently than a conventional sgRNA with 5′ matched GG residues at a second target within the same gene. Mutations generated by sgRNAs with 5′ GG mismatches are also heritable. We successfully obtained null mutants with detectable phenotypes from sib-mated mosaics after one generation. Conclusions In summary, our method improves the utility and flexibility of the ribonucleoprotein-based CRISPR/Cas9 system in silkworm.

A Review on Potential Antimutagenic Plants of Saudi Arabia

Mutagenic complications can cause disease in both present as well as future generations. The disorders are caused by exogenous and endogenous agents that damage DNA beyond the normal repair mechanism. Rapid industrialization and the population explosion have contributed immensely to changes in the environment, leading to unavoidable exposure to mutagens in our daily life. As it is impossible to prevent exposure, one of the better approaches is to increase the intake of anti-mutagenic substances derived from natural resources. This review summarizes some of the important plants in Saudi Arabia that might have the potential to exhibit anti-mutagenic activity. The data for the review were retrieved from Google scholar, NCBI, PUBMED, EMBASE and the Web of Science. The information in the study has importance since one of the major reasons for mutation is viral infection. Considering the pandemic situation due to novel coronavirus and its aftermath, the native plants of Saudi Arabia could become an important source for reducing mutagenic complications associated with exogenous agents, including viruses.

Oxidative Stress, Mutations and Chromosomal Aberrations Induced by In Vitro and In Vivo Exposure to Furan

Furan is a volatile compound that is formed in foods during thermal processing. It is classified as a possible human carcinogen by international authorities based on sufficient evidence of carcinogenicity from studies in experimental animals. Although a vast number of studies both in vitro and in vivo have been performed to investigate furan genotoxicity, the results are inconsistent, and its carcinogenic mode of action remains to be clarified. Here, we address the mutagenic and clastogenic activity of furan and its prime reactive metabolite cis-2 butene-1,4-dial (BDA) in mammalian cells in culture and in mouse animal models in a search for DNA lesions responsible of these effects. To this aim, Fanconi anemia-derived human cell lines defective in the repair of DNA inter-strand crosslinks (ICLs) and Ogg1−/− mice defective in the removal of 8-hydroxyguanine from DNA, were used. We show that both furan and BDA present a weak (if any) mutagenic activity but are clear inducers of clastogenic damage. ICLs are strongly indicated as key lesions for chromosomal damage whereas oxidized base lesions are unlikely to play a critical role.